Our bus was full when it left Tangiers, but it's even fuller now. Along the way we've picked up a dozen extra passengers and they're standing, crammed in the aisle, for a six-hour journey.

This is both illegal and dangerous, but not to worry - the surplus passengers don't officially exist. They won't show up in the bus company's records because they haven't got tickets. Instead, they have come to a private understanding with the driver and conductor.

Financially, this is a happy arrangement for all concerned. The extra passengers pay less than full fare, while the driver and conductor make some money on the side - which in turn saves the bus company the expense of paying them a decent wage.

Getting money is one thing, but hanging onto it in a poor country like Morocco is something else: other people want a share.

You can't go many miles along a main road without coming to a police checkpoint where officers are on the lookout for overcrowded vehicles, or those with bald tyres, smoky exhausts and other defects they'll be prepared to ignore in exchange for a few dirhams.

As we approach the checkpoints the conductor tells the standing passengers to sit on the floor so that they can't be seen through the windows.

The police order the bus to stop but they don't take a look inside. Instead, the conductor folds up a small banknote in the palm of his hand and gets out to greet one of the officers. He shakes hands with the policeman. The policeman's hand slides discreetly into his pocket and out again, then he waves us on. Everything is in order.

Last Monday a crowded bus on another route - from Marrakesh to Asni in the Atlas mountains - careered off the road and rolled down a hillside, killing 31 people and injuring 34.

Nobody in Morocco was terribly surprised by this, and the local media that bothered to report the tragedy had little to say beyond emphasising that King Mohammed had personally sent condolences to the victims' families and that the injured were being treated in military hospitals (ie the sort with decent facilities).

A full investigation into the accident has been promised but whatever it finds, you can be sure that any part played by roadside corruption will not be mentioned.

Cavalier approaches to safety are not just a Moroccan problem, but they are certainly a bigger problem in Arab countries than in the west. Nor is it just a matter of road accidents: the number of jerry-built houses in Egypt, for example, that fall down, killing their occupants, is quite amazing.

At one level, this can be blamed on a widespread sense of fatalism - that God alone determines whether we live or die. In most Middle Eastern countries if you get into a taxi and try to fasten your seat belt, the driver will, if he's in a good mood, merely ridicule you. The more macho ones treat it as defamatory comment on their driving skills. Many cars have colourful stickers on their dashboard saying, in Arabic calligraphy, "Ma sha' Allah" (Whatever God wills).

In the poorer countries, fatalism is coupled with a belief that safety is an expensive luxury. It is certainly cheaper to put your trust in God and buy a little sticker to say so, than to replace worn-out brake linings.

Sometimes this comes down to a choice between daily necessities and hypothetical possibilities. Imagine a family whose only source of income is the father's unroadworthy taxi. Should they go short of food in order to repair it, or carry on and pray that he won't have an accident?

That, of course, is where safety laws come in: to protect us from our own (and other people's) reluctance to take precautions. But laws in the Middle East are rarely what they seem. Often they exist, not for the public good, but for the good of those appointed to enforce them.

Anyone who is inconvenienced by a law can usually get round it by lubricating the bureaucracy with a little cash. Over time, this becomes the norm and laws serve only to generate income for the officials in charge.

Privately, most Arabs find the system disgusting. Some quote a verse from the Koran which says that the person who pays a bribe is as guilty as the person who receives it - but a refusal to pay can, at the very least, prove enormously time-consuming.

Others find ways to avoid a confrontation. One Moroccan of my acquaintance bought a stethoscope which he keeps on his car's dashboard where any policeman who stops him will see it and assume he's a doctor. Policemen, he says, are superstitious about harassing doctors lest they be struck down with sickness.

From time to time, when the level of grumbling gets too much, governments announce an anti-corruption drive. In Yemen, a couple of years ago, the president reportedly drove incognito from Sana'a to Aden to see how many policemen would ask for bribes along the way. That certainly scared a few people, but nothing more.

Once institutionalised, corruption becomes very difficult to eradicate. A good first step, in many countries, would be to reduce temptation by paying the police (and other officials) a decent salary. But that would mean putting up taxes - and persuading people to pay them without bribing the tax collectors.